The prevalence of erectile dysfunction (ED) in men visiting outpatient clinics was analyzed using data reported by 1352 randomly chosen physicians who were requested to interview five to 20 consecutive patients aged >or=40 years about the presence of ED. A total of 25.12% of the physicians returned the questionnaires, containing data on 3552 patients, of whom 42.7% had ED, 44.9% had no ED and 12.4% declined to answer the questions. The duration of ED was <1 year in 8.1% of patients, 1-2 years in 32.2% and >2 years in 59.7% of patients. 86.4% of men with ED had >or=1 chronic disease. ED was present in 70.3% of men with coronary heart disease, 67.8% of those with hypertension, 78% of those with diabetes and 70.5% of patients with psychiatric diseases. 93.2% of patients with ED used one or more drugs chronically. In conclusions, 42.7% of men visiting outpatient clinics had ED. Patients with ED often had one or more chronic diseases and used at least one drug chronically. Older patients are less inclined to talk to their physicians about sexual problems.